Erste klinische Erfahrungen mit einem neuen Großbildverstärker in der Thoraxdiagnostik

Abstract

In 350 patients with 870 pathologic findings comparative blind analysis of conventional chest films and biplane 100 mm photofluorographic images taken with the large-field image intensifier revealed high accuracy in the evaluation of coin lesions, hilar and pleural pathology, pulmonary vasculature and the right paratracheal stripe. Moderate central interstitial edema, more subtle interstitial changes particularly in the lung periphery including Kerley's B-lines, and calcifications in the hilum or the aortic arch are not visible in all cases for the evaluation of lesions of the ribs special films continue to be mandatory. Lateral views are of good quality. The spatial resolution of the large-field image intensifier was measured to be 4.5-5.2 LP/mm at the output phosphor, the spatial resolution of the 100 mm intensified images ranges from 2.6-3.8 LP/mm in the center. Mean skin dose was found to be 6.3 mrd in the p.a. projection which is less than 5% of the values registered in non-intensified photofluorography and even by factor 5 lower than in conventional chest x-ray using rare earth screens.

Large-Screen Image Intensifier Photofluorography Compared with Full-Size Screen-Film Technique in Chest Radiography

“…NEUFANG et coIl. (13) found that in photospot films, moderate central interstitial edema and more subtle interstitial changes, particularly in the lung periphery, including Kerley's B-lines were not always visible. However, a contributing cause may be the film viewer used.…”

“…(13) and RAITHEL et coll. (14) about the lack of definition in peripheral areas, especially in stout patients, and which was expressed in our work as poorer visibility of the finest vascular branches, and the lung apices on the lateral radiographs (Table 4), is evidently a consequence of a reduction in resolving power and density in field periphery (Fig.…”

“…Preliminary investigations (2,13,14) have revealed the usefulness of the image intensifier spotfilm technique in a number of radiographic diagnoses, such as pulmonary fibrosis, lung nodules, and pleural processes, measured as the sensitivity and specificity of the technique with reference to full-size radiography. The limitations of the technique, mainly lack of definition in minute details of peripheral lung fields have also been identified.…”

Large-Image Intensifier Photofluorography and Conventional Radiography in Pulmonary Emphysema

“…Preliminary investigations on large-image intensifier photofluorography in chest radiography have shown promising results, although inferior definition in the peripheral image field has been noted (6,10,12,14). In these studies, conventional chest radiography has been used as the reference technique, but the final value of this new imaging modality can be tested only in conjunction with clinical search for individual diseases using a separate and more accurate reference technique.…”

“…The spatial resolution of II photofluorography is only 70 to 90 per cent of that of most screen-film combinations used in chest radiography, and there is moderate electron-optical distortion in the peripheral image field (10). Good visualization of diagnostically important anatomic details in central parts of the chest have been reported in the preliminary studies on this imaging modality (10,12). Poorer visualization has been found in the peripheral field in comparison with conventional chest radiography.…”